Android app inkqubo – Uyenza njani i-Android Activity Lifecycle Callback kunye neSettingsFragment

Udweliso lwenkqubo ye-Android lucelomngeni kodwa lunengeniso oluya kukunika umda ngaphezu kwabo bakhuphisana nabo.. Inkqubo isekwe kwiminyaka yamava kuphuhliso lwesoftware kwaye ilungiselelwe ngokukodwa iimfuno zemveliso yakho. Kweli nqaku, siza kuchaza indlela yokwenza i-Android Activity Lifecycle Callback kunye neSettingsFragment. Siza kugubungela indlela yokusebenzisa iJava njengolwimi lwenkqubo ye-Android. Ekugqibeleni, inkqubo iya kukuthatha ukusuka ekuqaleni ukuya kwimveliso egqityiweyo.

IJava lulwimi lwenkqubo olukhethwayo kwiiapps zeAndroid

IJava yenye yezona lwimi zidumileyo zokucwangcisa ezisetyenziselwa uphuhliso lwe-Android app. Kukho amakhulu eapps kwiPlay Store ezibhalwe kwiJava. Ulwimi kulula ukulufunda kwaye lunolwimi olukhulu, uluntu oluxhasayo. Oku kuyenza ibe lukhetho olulungileyo kubaphuhlisi abafuna ulwimi olukhawulezayo noluthembekileyo ekwenzeni usetyenziso lweselula. Ezinye zezona zixhobo zidumileyo eziphuhliswe kwiJava ziquka i-Twitter kunye neSpotify.

IJava inikezela ngeseti etyebileyo yee-APIs, njengokwahlulahlula kwe-XML kunye noqhagamshelo lwedathabheyisi. Ikwalulwimi lwenkqubo oluzimeleyo kwiqonga, oku kuthetha ukuba abaphuhlisi ababhala ikhowudi yeJava banokuyisebenzisa kwiWindows, Linux, okanye iMac OS. Izibonelelo zokusebenzisa iJava kuphuhliso lweapp ephathwayo iyenza ibe lolona khetho lubalaseleyo kubaphuhlisi beselula.

IJava lolona lwimi ludumileyo lwenkqubo yokuphuhlisa usetyenziso, ngakumbi kwabaqalayo. Ulwimi lukwaxhaswa yi-Android Studio. Ngenxa yokuthandwa kwayo kunye nokusetyenziswa kwayo ngokubanzi, IJava lulwimi lwenkqubo olukhethiweyo lokuphuhlisa usetyenziso lwe-Android. Nangona kunjalo, kukho iingenelo zokusebenzisa ezinye iilwimi, njengoKotlin, kuphuhliso lweapp ye-Android.

IJava lulwimi olujoliswe kwinto eyenziwe yiSun Microsystems kwi 1995. Ineempawu ezinamandla zolawulo lwenkumbulo kwaye iyahambelana. Ikwaxhasa umqokeleli wenkunkuma ukulawula imemori kwikhowudi, eyenza lula ulawulo lwenkumbulo. Oku kuthetha ukuba ikhowudi yeJava ingaba yinde kwaye ibe nzima kunekhowudi yeKotlin.

Ngenxa yobuninzi bayo kunye nokuqina kwayo, IJava lolona khetho lubalaseleyo kuphuhliso lweapp ye-Android. Ulwimi kulula ukulufunda kwaye lusebenzisa amathala eencwadi avulelekileyo enza inkqubo ibe lula. Usetyenziso lweJava luyakwazi ukuxhasa iinkqubo ezininzi, into ebalulekileyo kwiinkampani ezineemfuno ezinzima. Bangakwazi kwakhona ukuphatha inani elikhulu labasebenzisi.

Enye indlela yokuphuhlisa usetyenziso lwe-Android yiCorona. ICorona ifundeka lula kuneJava kwaye isebenzisa ulwimi lweLUA. Ikwabonelela nge-SDK eyenza ukhowudo lube lula. Ineenzuzo ezininzi, njengokuhambelana nawo onke amathala eencwadi. Isenokusetyenziswa ukupapasha apps kwamanye amaqonga. ICorona isetyenziswa kakhulu ukwenza imidlalo. Ikhowudi ifakwe kumhleli wokubhaliweyo kwaye inokuqhutywa kwii-emulators ngaphandle kokuqokelela.

Ukuphuhlisa i-app ye-Android kufuna i-developmentsumgebung

I-developmentsumgebung yindawo ekuvumela ukuba uphuhlise usetyenziso lwezixhobo ze-Android. Kuyanceda ukuba usete i-app yakho ukuze isebenze ngokufanelekileyo kuzo zonke izixhobo ze-Android. Njengokuba, uya kufuna ukwenza iprojekthi ekuvumela ukuba usebenze ngezixhobo ezahlukeneyo kwizixhobo ezahlukeneyo. Iprojekthi kufuneka kwakhona kube lula ukuhamba kwaye kufuneka ibe nendawo ecocekileyo nelungelelanisiweyo. Kufuneka ikuvumele ukuba uphuhlise isicelo sakho ngaphandle kweengxaki.

Indawo ye-Android ifuna ukuba abaphuhlisi basebenzise iifayile ze-XML ukuchaza imitya ye-UI. Iifayile ze-XML zinokuchaza iimenyu, izimbo, imibala, kunye noopopayi. Ezi fayile zikwachaza uyilo lojongano lomsebenzisi. Ngokusebenzisa iifayile zeXML, unokwenza usetyenziso lwakho lusebenze kwizixhobo ezahlukeneyo kunye nezigqibo zokubonisa. Ungaphinda uchaze ezinye iifayile zoovimba kwiprojekthi yakho. Le ndlela, uya kuba bhetyebhetye ngakumbi kwixesha elizayo.

Ukwenza uMsebenzi we-Android Lifecycle Callback

Indlela yobomi bomsebenzi we-Android isetyenziselwa ukufumana ulwazi malunga nobume bomsebenzi, njengemeko yayo yangoku. Kwezinye iimeko, indlela yomjikelo wobomi iyasetyenziswa phambi kokuba umsebenzi utshatyalaliswe. Ukubona imveliso yale ndlela, ungasebenzisa i-logcat. Ikubonisa imveliso kwi-emulator, isixhobo, okanye zombini. Unako kwakhona ukubona umxholo kwi-logcat ye-onCresume, kwi Misa, kunye neendlela ze-OnStop.

Xa umsebenzi uqaliswa kwakhona, inkqubo iyakubiza i-OnResume() buya utsale umnxeba. Kuya kufuneka uthathe ithuba lesi siganeko ukugcina imeko kwinkumbulo, nokuba umsebenzi wakho ubunqunyanyisiwe. Le ndlela, abasebenzisi bakho baya kuba nokufikelela ekusebenzeni kwe-app yakho ngelixa umsebenzi unqunyanyisiwe.

Indlela yokufowunela umjikelo wobomi kwakhona ingasetyenziselwa ukujongana notshintsho phakathi kweemeko ezahlukeneyo zomsebenzi. Umzekelo, Isidlali sevidiyo esidlalayo sinokunqumama kwaye siqalise ividiyo kwakhona xa umsebenzisi etshintsha usetyenziso. Inokuphelisa unxibelelwano lwayo lwenethiwekhi xa umsebenzisi etshintshela ii-apps. Kwaye, xa umsebenzisi ebuya, inokuphinda iqalise ividiyo kwindawo enye ebeyishiyile.

Nje ukuba kwenziwe umsebenzi, iya kuhamba nge-onCreate() kwaye onDestroy() iindlela. Ezi ndlela ziya kubizwa kube kanye kuphela ngexesha lomjikelo wobomi bomsebenzi. Nangona kunjalo, ukuba umsebenzisi uvala isicelo phambi kokuba umsebenzi ugqitywe, kwiSaveInstanceState() I-callback iya kubizwa.

Ngaphandle kokudala umsebenzi, Ungasebenzisa kwakhona i-onStart() indlela yokuqalisa kwakhona umsebenzi. Le ndlela ibizwa ngokuba yinkqubo ye-Android emva kokuba idale umsebenzi. Kwaye, emva kokuba umsebenzi umisiwe, inokuphinda iqalwe ngokutsha ngokufowunela qala kwakhona. Oku kunokunceda inkqubo igcine ezinye iinkqubo ezinokusebenza kamva, ngaloo ndlela kuphuculwe ukusebenza ngokubanzi kwesicelo. Nangona kunjalo, uya kufuna ukuqwalasela iinkcukacha ezimbalwa phambi kokusebenzisa obu buchule.

Inyathelo lokuqala ekudaleni i-Android Activity Lifecycle Callback kukuqonda indlela abafowunelwa abasebenza ngayo kwaye xa becelwa.. Eyokuqala ibizwa ngokuba yi-Dala(). Xa le ndlela isetyenziswa, umsebenzi uyadalwa kwaye udala zonke iimbono eziyimfuneko, izibophelelo, kunye nezintlu. Emva kwe-OnCreate() buya utsale umnxeba, i-OS iya kugqithisela ulawulo kwi-OnResume() okanye kwiDestroy().

Ukwenza i-Android SettingsFragment

Xa ukwakha isicelo Android, ungasebenzisa iPreferenceFragment ukwenza iphepha lezicwangciso likhangeleke limnandi kwaye lifana. Oku kuya kuqinisekisa ukuba abasebenzisi bakho banamava angaguqukiyo omsebenzisi nokuba bajonge luphi useto. Ukusebenzisa olu hlobo lwecandelo, kufuneka wandise iklasi ye-PreferenceActivity. Emva koko, kufuneka usebenzise i-onBuildHeaders() buya utsale umnxeba.

Unokwenza iiFragments ezikhethekileyo. La maqhekeza luyilo olubhetyebhetye ngakumbi kunomsebenzi wakho oqhelekileyo. Amaqhekeza ngokwesiseko amacandelo eemodyuli zomsebenzi wakho, kwaye babe nomjikelo wabo wobomi. Bakwafumana eyabo imicimbi yegalelo. Ngaphaya koko, unokongeza amaqhekeza kwi-app yakho ngelixa iqhuba.

I-PreferenceFragment licandelo elinoluhlu lwezinto ezikhethwayo. Isetyenziswa kwii-apps ze-Android kwaye igcina useto olukhethwayo kwi-SharedPreferences. Ayiwuxhasi umxholo woyilo lweMaterial, nangona kunjalo. Kuyenzeka ukwandisa iDialogPreference kunye neTwoStatePreference ngokusebenzisa useto lwe-API.

Ukuba i-app yakho yenzelwe ukuba yenzelwe wena ngakumbi, ungasebenzisa iPreferenceFragment. Le klasi icetyiswa kwi-Android 3.0 nangaphezulu. Ikuvumela ukuba wenze ngokwezifiso inkangeleko kunye nokuziva kwe-app yakho. Unokwenza umzobo wojongano lomsebenzisi kwisicelo sakho. Uyilo nalo luyakwazi ukwenzeka kakhulu.

I-PreferenceFragment yindlela efanelekileyo yokugcina izinto ozikhethayo. Xa utshintsha ukhetho kwi-app yakho, I-Android iya kuzigcina ngokuzenzekelayo utshintsho kwifayile yeSharedPreferences. Kodwa oku kuthetha ikhowudi engaphezulu yokusingatha utshintsho. Ii-apps ezininzi kufuneka zimamele utshintsho kwifayile yeSharedPreferences.